POS0741 REPORT FROM THE APS STUDY GROUP OF THE ITALIAN SOCIETY FOR RHEUMATOLOGY (SIR-APS) ON aPL NEGATIVIZATION
Authors: S. G. Foddai, S. Sciascia, C. Alessandri, A. Alunno, L. Andreoli, A. Barinotti, A. Calligaro, V. Canti, F. Carubbi, I. Cecchi, C. Chighizola, F. Conti, G. Emmi, A. Fioravanti, F. Fischetti, F. Franceschini, M. Gerosa, A. Hoxha, M. Larosa, M. G. Lazzaroni, C. Nalli, G. Pazzola, M. Radin, B. Raffeiner, V. Ramoni, D. Roccatello, E. Rubini, G. Sebastiani, S. Truglia, M. L. Urban, A. Tincani
Journal: Annals of the Rheumatic Diseases (2022)

Background The rate of antiphospholipid antibodies (aPL)negativization in antiphospholipid syndrome (APS) patients is uncertain, but it is estimated to be as high as 8%. aPL disappearance seems to be more frequent in patients positive for one single aPL test and appears to be related with the immunosuppressant/immunomodulatory treatment undertaken by the patient. Currently, a consensus definition of aPL negativization is lacking, as well as international recommendations on how to approach treatment in patients with a persistent aPL negative seroconversion. Objectives The aim of our work was to evaluate the clinical approach and the level of consensus among experts from the APS Study Group of the Italian Society for Rheumatology (SIR-APS) in different clinical scenario addressing aPL negativization and its definition. Methods Experts of SIR-APS were contacted using a survey methodology. Results A structured survey was circulated among 30 experts.Up to 90% of the interviewed experts agreed on defining aPL negativization as the presence of two negative determinations, one year apart (90% ). Almost ful lconsensus exist among experts in some clinical settings, including: a) the role of aPL negativitation in the management of a thrombotic event determined by concomitant presence of cardiovascular risk factors, both modifiable and not modifiable (90%): b) approach to young patients with triple aPL positivity who experienced pulmonary arterial thrombotic event and tested negative for aPL detection after five year of vitamin K antagonist (VKA) treatment (90%); c)the use of “ extra criteria ” aPL antibodies testing before pondering VKA suspension (93%). Conclusion Consensus is needed to support the management of patients with APS in areas where controlled data are missing. A substantial agreement exists among expert in defying aPL negativization as the presence of two negative determinations, one year apart. On the contrary, VKA suspension should be embraced with extreme caution when it comes to APS patients, particularly if they experienced arterial thrombotic events and/or tested positive for triple aPL. Nevertheless, VKA cessation might be considered when risk factors are carefully monitored/treated and the presence for “ extra criteria” aPL is ruled out. References [1]Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, Cervera R, Derksen RHWM, DE, Groot PG, Koike T, Meroni PL, Reber G, Shoenfeld Y, Tincani A, Vlachoyiannopoulos PG, Krilis SA. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost 2006; 4: 295–306. [2]Coloma Bazán E, Donate López C, Moreno Lozano P, Cervera R, Espinosa G. Discontinuation of anticoagulation or antiaggregation treatment may be safe in patients with primary antiphospholipid syndrome when antiphospholipid antibodies became persistently negative. Immunol Res Immunol Res; 2013; 56: 358–61. [3]Radin M, Schreiber K, Sciascia S, Roccatello D, Cecchi I, Aguirre Zamorano MÁ, Cuadrado MJ. Prevalence of Antiphospholipid Antibodies Negativisation in Patients with Antiphospholipid Syndrome: A Long-Term Follow-Up Multicentre Study. Thromb Haemost 2019; 119: 1920–6. Acknowledgements Italian Society of Rheumatology Disclosure of Interests None declared